Transcript Marine Ecology, Ecosystems, Marine Factors, Seawater Chemistry

Marine Ecology
• Marine ecology is the branch of
ecology dealing with the
interdependence of all organisms
living in the ocean, in shallow coastal
waters, and on the seashore.
• The marine environment for all
organisms consists of non-living,
abiotic factors and living, biotic
factors.
Abiotic
The abiotic factors include all the physical,
chemical and geological variables that
have a bearing on the type of life that can
exist in an area. Included are:
pH
water
tides
salinity
temperature
light
Nutrient supply
currents
Dissolved gases
waves
pressure
substratum
exposure to air
Biotic
• Biotic factors are the interactions
among living organisms.
Examples might be:
•another organism
•predators
•food availability
•reproduction
Pelagic zone
• waters of the world
• The pelagic zone include
the productive coastal
waters,
• neritic zone, and …
• deep waters of the open
ocean, oceanic zone.
• Another division in the
pelagic zone is related to
light penetration.
– photic zones
– aphotic zones
Pelagic zone continued
• Organisms living in
pelagic waters also put
up with changes in
salinity, temperature etc.
• Inhabit the coastal areas etc. which fit their
adaptations.
• Can withstand large changes (eury-- prefix)
and narrow tolerance (steno).
Benthic zone
• the ocean bottom
• extends from the seashore to
the deepest parts of the sea.
• The material that makes up
the bottom is the substratum
and the organisms living there
are the benthos.
Benthic zone continued
• tides uncover parts of this zone
• the area uncovered is the intertidal zone
Benthic zone continued
• above is the supratidal
zone affected by salt spray
but not covered by sea
water
• below the intertidal zone is
the subtidal zone,
submerged and extending
seaward.
Benthic zone continued
• The elevation and slope determines
the length of time its exposed.
• This affects organisms living there
because some are restricted to zones
according to their adaptations to this
type of zone (intertidal etc.).
Other zones
• include the surface
waters of the coastal
areas called the
neritic zone
• epipelagic zone ~ the
surface waters of the ocean.
• The open ocean is less productive
than the neritic zone which contains
plant plankton, fish larva,
invertebrate larva that will
eventually end up near the coast.
The open ocean is divided
into zones depending on
the amount of light it
receives
• ...from the epipelagic layer to the mesopelagic
zone 200-1000m in which daytime inhabitants
migrate upwards during the night, bringing back
nutrients and some exhibit bioluminescence (light
producing organs called photophores).
• The deep sea layers bathypelagic 1000-4000m
and the abyssopelagic zone (below 4000m) have
limited food supplies although bacteria have been
found that can make their own food.
Ocean
Divisions
and
Zones
Fig. 2-24
text
pg# 39
Marine Organism Lifestyles
• Plankton
– Organisms that drift with
ocean currents
• Nekton
– Organisms that are
active swimmers and
can move against the
ocean currents
• Benthos
– Organisms that live on,
in or near the sea floor